二尖瓣脱垂（） A.Craham-Steel杂音 B.Austin-Flint杂音

（8分）物质的性质与变化

老师在课堂上演示了如下3个有趣的实验：

①用坩埚钳夹持一小块石灰石，用酒精灯加热，2分钟后把石灰石放入含有酚酞的蒸馏水中，酚酞溶液不变色。

②用坩埚钳夹持该石灰石，还用酒精灯加热，同时向灯焰上通入氧气，1分钟后把石灰石再放入含有酚酞的蒸馏水中，酚酞溶液立即变成红色。

③向②变红的酚酞溶液中逐滴滴加盐酸，酚酞溶液又变为无色。

请回答下列问题：

（1）下列说法不正确的是（     ）

A．石灰石不具有受热分解的化学性质

B．实验①中，在受热的条件下，石灰石没有发生化学变化

C．化学反应需要一定的条件，在实验①中，灯焰温度达不到石灰石分解的温度

（2）通入氧气，能影响碳酸钙分解反应的原因，正确的是（ ）

A．氧气能降低碳酸钙分解所需的温度

B．氧气能改变碳酸钙的性质

C．氧气是碳酸钙分解反应的催化剂

D．增加了单位时间内酒精分子与氧分子发生有效碰撞的次数，提高了灯焰温度

（3）在初中阶段，涉及到的物质的化学性质主要有：

A.可燃性；B.热稳定性；C.酸性；D.碱性；E.金属活动性；F.非金属活动性。

在上述变化中，酒精表现出的化学性质是（填代号，下同）      ；盐酸表现出的化学性质是        。

（4）写出上述实验中发生的有关反应的化学方程式：

原始材料的重点是选择优良的（），这是系统育种的基础。

戴望舒在《雨巷》中塑造的抒情形象是（）

A.年轻的女郎

B.丁香姑娘

C.翠翠姑娘

D.七斤嫂

I got a job teaching special education at a school in Coachella, California, a desert town about 170 miles from home. It was no (1) job. Street gangs (2) around the school after dark."Be careful," Dad warned me during one of my frequent weekend (3) home. He was concerned about my living (4) , but I needed to be on my own.One evening, I stayed after school to rearrange my classroom. (5) , I turned out the light and closed the door. Then I (6) toward the gate. It was (7) ! I looked around. Everyone had gone home.After (8) all the exits, I found just enough (9) to squeeze under a gate in the back of the school. Then I walked toward my car, parked in a field behind the building.Suddenly I heard voices. I (10) around and saw at least eight boys following me. (11) my pace, I reached into my shoulder bag to get my key. I (12) all over the inside of my handbag. But the key wasn’t (13) ! Dear Lord, please help me, I prayed (14) . Suddenly, my fingers touched a loose key in my purse. I didn’t even know if it was for my car, but I took it out and (15) it. It worked!I opened the door, slid in and locked it—just (16) the teenagers surrounded the car. Trembling , I started the engine and (17) away. When I returned to my apartment, the phone was ringing. It was my Dad. I didn’t tell him about my experience; I didn’t want to (18) him. "Oh, I forgot to tell you!" He said, "I had a(n) (19) car key made and slipped it into your purse—just (20) you ever need it.

第（7）空应选择（）

A．closed

B．locked

C．stuck

D．opened

中国历史上到印度取经的佛教徒中成就最卓著之人是谁著有什么著作